Projecting teleprinter with platen movable into and out of projection field



Aug. 17, 1965 F. A. MOORE 3,200,928

PROJECTING TELEPRINTER WITH PLATEN MOVABLE INTO AND OUT 0F PROJECTION FIELD Filed April 1, 1963 2 Sheets-Sheet 1 lnvenlor FRANK A. MOORE Aug. 17, 1965 3,200,928

F. A. MOOR PROJECTING TELEPRINTER WITH PLATEN MOVABLE INTO AND OUT OF PROJECTION FIELD Filed April 1, 1965 2 Sheets-Sheet 2 Inventor FRANK A. MOORE B lv/A tare United Sates Patent ice 3,230,928 PROJECTENG TELEPRINTER WITH PLATEN MQVABLE INTO AND GUT F PRQEEC- TION FKELD Frank Arthur Moore, 'Croydon, Surrey, England, assignor to Creed 8; Qornpany Limited, Croydon, Saurrey, England, a dh'itish company Filed Apr. 1, 1963, Ser. No. 259,348 Claims priority, application Great Britain, Apr. 18, 1962, 15,07 1/ 62 2 Claims. (Cl. 19755) This invention relates to typeprinting apparatus.

In the typeprinting apparatus to be described herein, an improved form of printing platen is disclosed in which the platen is moved into the path of the typeprinting head to a printing position just before a printing operation is to take place and retracted from that position to a rest position after the printing operation, at which time a character so printed, together with other of a line or lines of print may be projected onto a screen without obstruction of the image by the platen. The rapidity with which characters are printed and with which the platen is moved into and out of the path of the typehead is such that the printed text appears visible to the eye throughout printing operations.

According to one aspect of the present invention therefore, there is provided typeprinting apparatus including a typehead mounted on a carriage, means for rocking said carriage and typehead towards a printing medium to print a character thereon and for rocking said carriage and typehead away from the printing medium after printing of the character, a platen bar, and means for moving the platen bar from a rest position to a printing position in which it supports said medium prior to and during a printing operation, and for retracting said platen bar from said printing position to said rest position after said printing operation has been effected.

According to a further aspect of the present invention there is provided typeprinting apparatus including a type head mounted on a carriage, means for rocking said carriage and typehead towards a printing medium to print a character thereon and for rocking said carriage and typehead away from the said printing medium after printing of the character, a platen bar arranged for movement between a rest position and a printing position which movement is in a direction at a right angle to a line of print on said medium, and means for moving said platen bar to said printing position in which it extends parallel to the line of print and supports said medium prior to and during a printing operation and for retracting said platen bar from the printing position to the rest position after said printing operation has been effected.

The invention will be better understood from the following description read with reference to the accompanying drawings in which:

FIG. 1 shows a pictorial view of an embodiment of the invention and,

FIG. 2 shows an end elevation of the embodiment of FIG. 1, together with an optical arrangement for projecting printing characters onto a screen in an enlarged form.

Referring firstly to FIG. 1, this figure shows a pictorial view of part of a teleprinter of a well-known type in which a typeprinting head 1 on a carriage 2, is rocked about the axis of a shaft 3, in a direction indicated by the arrow A from a rest position to a printing position. The carriage 2, with printing head 1 thereon, is movable in the direction indicated by the arrow B to effect letterfeed steps in that direction. In this embodiment a guide roller 5, formed by a conventional roller-type printing platen, is carried on a rotatable shaft 6 between support 3,25%,928 Patented Aug. 1?, 1965 members 7 of the apparatus frame. This is: in a position below that which it would occupy if it were serving its normal function, but as already mentioned it serves only as a guide for the printing medium 4. The medium is of translucent material through which light. may be projected in a manner later to be described. The axis Y-Y about which the roller 5 normally rotates serves as an axis for a platen bar 8 which is affixed at its ends to arms 9. The arms 9 are pivotally mounted in pins such as 19, affixed to support members 7, and urged anticlockwise about the axis of pins 10 by tension springs such as 11. The tension springs 11 are afiixed at their ends to support members 7 and arms 9 by pins such as 12 afiixed the the members. Each arm a carries a trunnion block such as 13, pivotally affixed thereto, each trunnion block being engaged by a cranked men er, such as 14, pivotally mounted on the support members 'i by a pin, such as 15. The lower extensions, such as 15, of the cranked members 14 each carry a pin, such as 17, on which there is pivotally mounted one half of a link member 18 the other half of which is pivotally carriedpby way of an elongated hole 1? therethrough, on the stub end of a bar 21 which is carried by and atiixed to the carriage 2. The halves of the link members 18 are afiixed one to another by screws, such as 21 which extend through elongated slots (not shown) in the left-hand halves of the link members into tapped holes in the right-hand halves. This division of the link members 13 into two halves, is to permit adjustment to be made to the length of the link members so that the platen bar 8 is in a printing position to support the medium for printing thereon just prior to the printing operation being effected. The purpose of providing this method of adjustment will become more apparent later in the description. Stops, such as 22, are affixed to support member '7 by way of screws, such as 23. It is the purpose of these stops to prevent the platen bar 8 from moving past the printing position with respect to the printing head 1 during pivoting movement about the axis of pins 11 in an anticlockwise direction.

Referring now to FIG. 2, this figure shows a side elevation of the apparatus and the optical system for projecting the text printed on the translucent medium 4 onto the screen.

The optical system comprises a light source 24, a condensing lens assembly 25, a mirror 26, a projector lens assembly 27, a mirror 28, and the screen 29. The arrows D denote the direction of projection of the image of the text printed on the medium 4. In FIG. 2 the platen bar 8 is in the rest position i.e., the retracted position to which it is moved after printing. When a character is to be printed the type head 1 is moved upward in the direction indicated by the arrow from the position shown in dotted lines to the position in which it is shown in full lines, and the carriage 2 is rocked about the axis of the shaft 3, in the direction indicated by the arrow A, to move the typehead 1 from the rest position to the printing position. In its movement the carriage 2, by way of bar 20, and link members 13, causes the cranked members 14 to pivot about the axis of pins 15 in a clockwise direction. This pivoting movement, by way of trunnion blocks 13 permits arms 9 to pivot in an anticlockwise direction, about the axis of pins 1%, under the influence of tension springs 11 so that the platen bar it is pivoted in the same direction from the rest position to the printing position. This movement of the platen bar it is at a right angle to the line on which printing is to be effected, and when in the printing position the platen bar it occupies a position parallel to that line and directly behind it so that it supports the medium 4- whilst printing is taking place. Referring new again to FIGQ 1, this figure shows the platen bar 8 in the printing position at the end of its pivoting movement. The pivoting movement of the bar is arrested through engagement of the ends of the upper limbs of the cranked members 14 with stops 22. At this time however, the type head 1 has not yet completed its full pivoting movement in the anti-clockwise direction, and continues to pivot with the stub ends of the bar 20 moving in the elongated slots in link members 18. Movement of the carriage 2 terminates when the character on the typehead ll selected for printing, has effected a printing operation by striking the medium 4 at the required character position thereon. As stated previously, when the platen bar 8 is in a printing position it is directly behind the printing medium 4, and supports the medium as it is struck by the typehead 1. As soon as the printing operation has been effected, the carriage 2 is rocked about the axis of the shaft 3 in a direction reverse to that indicated by the arrow A, toward the rest position, and the typehead 1 is lowered to occupy the position in which it is shown as a dotted outline (FIG. 2). When, during this rocking movement of the carriage 2, the stub ends of the bar 20, carried by carriage 2, engage the right-hand ends of elongated slots in the link members 18, the link members move to the right to cause cranked members 14 to pivot about the axis of pins 15 in an anti-clockwise direction. This pivoting action of the cranked members 14 through trunnion blocks 15, cause arms 9 to pivot about the axis of pins in a clockwise direction against the influence of tension springs 11, so that the platen bar 8 carried by the arms 9 pivots in the same direction and is retracted from the printing position to the rest position. With the typehead 1 in its lower position and the platen bar 8 retracted to the rest position, there is no obstruction for the passage of light from source 24, via lens system 25, through the printing medium 4 to mirror 26 and so on to screen 29, and thus the printed text and the last character to be printed is visible on the screen.

This process of moving the platen bar 8 from the rest position to the printing position and vice versa continues as long as printing is being etfected on the printing medium 4. In order to ensure that the printing platen 8 is in the printing position before the typehead 1 strikes the printing medium, initial adjustment of the relative positions of the typehead 1 and platen bar 8 is made. This is eifected by loosening screws 21, which lock the halves of the link members 18 together, and adjusting the halves of the link members 18 to their fullest extent. Thereafter screws 21 are retightened and the carriage is rocked manually to move the typehead towards the printing position. When cranked arms 14 engage with stops 22 the platen bar 8 is in the printing position and typehead 1 will be approaching the printing position. Screws 21 are then loosened and the position of the typehead 1, with respect to the printing position is adjusted so that the typehead reaches the printing position with the required delay after the platen bar 8 has reached that position, screws 21 are then retightened. The apparatus described herein is particularly suitable for the projection of items of news interest as such items are received by the teleprinter, and for further display by a television system, the camera of which is focussed on the apparatus screen.

It is to be understood that the foregoing description of specific examples of this invention is not to be considered as a limitation on its scope, as set forth in the accompanying claims.

What I claim is:

1. Typeprinting apparatus including a typehead mounted on a carriage, means for rocking said carriage and typehead towards a printing medium to print a character thereon and for rocking said carriage and typehead away from said printing medium after printing of said charactor, a pair of pivots positioned rearwa'rdly of a printing position, a pair of arm members pivotally mounted on said pivots respectively, a platen bar mounted on said arm members for vertical movement, and means for moving said platen bar from a rest position in which said platen bar is retracted below a printing position to said printing position in which it supports said medium prior to and during a printing operation, and for retra-cting said platen bar from said printing position to said rest position after said printing operation has been effected, said platen-bar-moving means being constituted by said carriage, means being provided to interconnect said carriage and said platen bar 50 that said platen bar is moved from said rest position to said printing position as said typehead is rocked with the carriage theretoward and so that said platen is retracted from said printing position as said typehcad is rocked with said carriage towards said rest position, said last-mentioned means comprising a bar member carried by said carriage and means connecting said bar member to said arm members to pivot said arm members in response to movement of said bar member by said carriage.

2. Typeprinting apparatus comprising a field of view, means including a beam of light passing through said field for projecting an image of said field, a light-permeable printing medium, means for positioning said printing medium in said field in said beam of light, a carriage, a typehead mounted on said carriage, means for mounting said carriage in such a position that said carriage and said typehead are outside of said light beam when in position of rest, and in such a manner that said carriage may be moved to cause said typehead to move into printing engagement with said printing medium within said field, a pair of pivots positioned rearwardly of a printing position, a pair of arm members pivotally mounted on said pivots respectively, a platen bar mounted on said arm members for vertical movement into the path of said light beam at the opposite side of said printing medium from said typehead and to a point cooperating with said typehead to form a backing therefor when said typehead is in printing engagement with said printing medium, means for simultaneously moving said carriage and said platen member to position said platen member is said field in printing position against one side of said printing medium and said typehead thereafter to strike the other side of said printing medium for printing engagement therewith where it is packed by said platen member, and means operable immediately after the printing engagement for simultaneously moving said platen member away from said beam of light and moving said carriage so as to move said typehead away from said beam of light, said moving means comprising a bar member carried by said carriage and means connecting said bar member and said arm members to pivot said arm members in response to movement of said bar member by said carriage, said moving means operating at such a speed that the appearance of the projected image of said field is unimpaired.

References Cited by the Examiner UNITED STATES PATENTS 936,497 10/09 Webster 88-24 1,980,160 11/34 Benjamin 8824 X 2,115,456 4/38 Chisholm 197-66 2,252,577 8/41 Newman 8824 2,307,433 1/43 Unkles 88-24 2,330,799 10/43 Coker et a1. 8824 2,405,168 8/46 Schuler 88-24 FOREIGN PATENTS 821,944 11/51 Germany.

ROBERT E. PULFREY, Primary Examiner. EUGENE R. CAPOZIO, Ex'aminer. 

1. TYPEPRINTING APPARATUS INCLUDING A TYPEHEAD MOUNTED ON A CARRIAGE, MEANS FOR ROCKING SAID CARRIAGE AND TYPEHEAD TOWARDS PRINTING MEDIUM TO PRINT A CHARACTER THEREON AND FOR ROCKING SAID CARRIAGE AND TYPEHEAD AWAY FROM SAID PRINTING MEDIUM AFTER PRINTING OF SAID CHARACTER, A PAIR OF PIVOTS POSITIONED REARWARDLY OF A PRINTING POSITION, A PAIR OF ARM MEMBERS PIVOTALLY MOUNTED ON SAID PIVOTS RESPECTIVELY, A PLATEN BAR MOUNTED ON SAID ARM MEMBERS FOR VERTICAL MOVEMENT, AND MEANS FOR MOVING SAID PLATEN BAR FROM A REST POSITION IN WHCIH SAID PLATEN BAR IS RETRACTED BELOW A PRINTING POSITION TO SAID PRINTING POSITION IN WHICH IT SUPPORTS SAID MEDIUM PRIOR TO AND DURING A PRINTING OPERATION, AND FOR RETRACTING SAID PLATEN BAR FROM SAID PRINTING POSITION TO SAID REST POSITION AFTER SAID PRINTING OPERATION HAS BEEN EFFECTED, SAID PLATEN-BAR-MOVING MEANS BEING CONSTITUTED BY SAID CARRIAGE, MEANS BEING PROVIDED TO INTERCONNECT SAID CARRIAGE AND SAID PLATEN BAR SO THAT SAID PLATEN BAR IS MOVED FROM SAID REST POSITION TO SAID PRINTING POSITION AS SAID TYPEHEAD IS ROCKED WITH TH CARRIAGE THERETOWARD AND SO THAT SAID PLATEN IS RETRATED FROM SAID PRINTING POSITION AS SAID TYPEHEAD IS ROCKED WITH SAID PRINTING WARDS SAID REST POSITION., SAID LAST-MENTIONED MEANS COMPRISING A BAR MEMBER CARRIED BY SAID CARRIAGE AND MEANS CONNECTING SAID BAR MEMBER TO SAID ARM MEMBERS TO PIVOT SAID ARM MEMBERS IN RESPONSE TO MOVEMENT OF SAID BAR MEMBER BY SAID CARRIAGE. 